DESCRIPTION The invention relates to a device for glueing foam sections together, said device comprising a glueing station provided with first positioning means for positioning a first foam section, second positioning means for positioning a second foam section, application means for applying glue to the first foam section and/or the second foam section, moving means for moving the first positioning means and the second positioning means towards and away from each other in a direction of movement for placing the first foam section and the second foam section into contact with each other for the purpose of glueing together the same and subsequently holding the first and the second foam section in glued-together condition in the second positioning means.

Such a device is known from US patent No. 4,572, 762.

In the so called lost foam production process, a correspondingly shaped foam pattern must be provided for each moulded product to be produced. As the complexity of the geometry of the final moulded product to be produced increases, the complexity of the geometry of the required foam patent will logically increase accordingly. For that reason, the foam patters are generally built up of two or more foam sections, which are glued together. The accuracy with which said glueing takes place (partially) determines the accuracy of the final moulded product.

US patent No. 4,572, 762 discloses a device by means of which two foam sections can be glued together. The foam sections to be glued together are retained in a lower retainer and an upper retainer, respectively. The lower retainer is capable of vertical movement for placing the foam sections into contact with each other upon upward movement. The upper retainer is capable of lateral movement to a position above a glue plate which is capable of a vertical movement between a lower position, in which the glue plate is submerged in a tank containing a hot glue, and an upper position, in which the glue plate abuts against the foam section being retained in the upper retainer for transferring hot glue to the foam section in question. Thus, the foam section in the upper retainer can be provided with the hot glue that is necessary for effecting the glued joint between the two foam sections before the foam sections are forced into contact with each other. Furthermore, to make it possible to load a foam section into the upper retainer, the upper retainer can be pivoted about a horizontal axis so as to place the upper retainer in an advantageous position and orientation for loading a foam section.

An important limitation of the device disclosed in US 4,572, 762 is the fact that said device is not suitable for glueing together more than two foam sections, which, as already indicated above, is generally necessary or at least highly desirable in the case of complex geometries of foam sections. The object of the present invention is to provide a device which, unlike the prior art device, is suitable for glueing together more than two foam sections. More specifically, it is an object of the present invention to provide a device which makes it possible to glue together two or more foam sections in a highly accurate manner. Another object of the present invention is to provide a device that is suitable for glueing together two or more of foam sections in a highly automated process, or, in other words, with a minimum degree of human interference. To that end, the device according to the invention is in the first place characterized in that the device comprises a further glueing station as well as conveying means for conveying the second positioning means from said glueing station to said further glueing station, said further glueing station being provided with further first positioning means for positioning a further foam section, further application means for applying glue to the glued-together first and second foam sections and/or said further foam section, further moving means for moving said second positioning means and said further first positioning means towards and away from each other for placing the already glued-together first and second foam sections on the one hand and said further foam section on the other hand into contact with each other for the purpose of glueing said sections together and subsequently holding said first, said second and said further foam section in glued- together position in said second positioning means or said further first positioning means. The use of a further glueing station and of conveying means for conveying the second positioning means of the glueing station to the further glueing station makes it possible to interconnect three or, if more than one further glueing station is used, four or more foam sections in a fully automated process by glueing them together.

Preferably, the conveying means are arranged for conveying the second positioning means back and forth between said glueing station and said further glueing station. Thus the device as a whole can be of modular structure, comprising a (base) glueing station and further glueing stations arranged in series therewith, without there being a need to have the second positioning means travel along an endless conveying path, which would have this drawback that more second positioning means than (further) glueing stations would have to be provided in practice and that the conveying path, insofar as extending from the last glueing station and back to the (base) glueing station, would take up additional space in a production environment.

From a constructional point of view it is advantageous if the conveying means comprise guide means for conveying the second positioning means along said guide means.

Preferably, further second positioning means are provided, which can likewise be conveyed by the conveying means. Thus, the capacity of the device can be increased in that foam sections, which may or may not be of compound construction, can be glued together with other foam sections in the (further) second positioning means at several glueing stations simultaneously.

It is advantageous in this connection if said second positioning means and said further second positioning means are interconnected for joint transport, e. g. along the guide means. This achieves that said second positioning means and said further second positioning means will follow the same pattern of movement, as a result of which synchronisation problems between said second positioning means and said further second positioning means are avoided.

In order to position the foam sections to be glued together as accurately as possible with respect to each other, the first positioning means and the second positioning means preferably comprise centring means having intermating centring means on the respective first positioning means and second positioning means for aligning the first foam section and the second foam section with respect to each other upon placing the first foam section and the second foam section into contact with each other.

Furthermore preferably, said centring means are arranged for aligning the first foam section and the second foam section in a direction perpendicular to the direction of movement before the first foam section and the second foam section are placed into contact with each other. An important advantage of this arrangement is that glue is prevented from being spread over the boundary surface between the first foam section and the second foam section, which might have a negative effect on the quality of the glued joint.

A constructionally advantageous solution to this problem is obtained if the first positioning means or the second positioning means comprise a frame member and a retainer section comprising a retainer for holding a foam section in position, which retainer section is movable against a first spring force in the direction of movement and in a direction perpendicular to the direction of movement with respect to the frame member, said retainer section being provided with at least one centring member.

According to an especially preferred embodiment, at least one pin member is connected to one of said frame member and said retainer section, which pin member extends with some play through an associated hole of the other of said frame member and said retainer section, being provided with a head that is to offer resistance against said first spring force. The presence of play between said at least one pin member and said associated hole enables movement of the retainer section in a direction perpendicular to the direction of movement.

To enable movement of the retainer section with respect to the frame member in a direction perpendicular to the direction of movement in all directions lying in the plane perpendicular to the direction of movement, it is important for said at least one pin member to extend centrally in said associated hole in a starting position. To achieve this, said centring means preferably comprise a bevelled circumferential edge on said at least one pin member and/or said associated hole.

In addition to that, said at least one centring member is preferably connected to said retainer section against a second spring force, as a result of which additional space and time can be obtained between the moment the centring members start to interact and the moment the foam sections to be interconnected come into contact with each other.

The application means preferably comprise a reservoir for glue as well as a glueing element that is to make contact with a foam section for the purpose of applying glue to said foam section, said reservoir and said glueing element being movable with respect to each other between a first position, in which the glueing element is submerged in the glue, and a second position, in which the glueing element is clear of the glue in the reservoir.

The glueing element preferably takes up a fixed spatial position during the relative movement of the reservoir and the glueing element between said first and said second position. In this way the accuracy with which the glueing element is eventually positioned for contact with a foam section is optimised. Preferably, only the foam section is spatially moved so as to place a foam section and the glueing element into contact with each other, with the glueing element taking up a fixed spatial position, since the foam sections need to be movable anyway with a view to placing two foam sections into contact with each other and realising the associated manipulation of the foam sections.

To make it possible to apply glue accurately to one foam section or to both foam sections to be interconnected, the application means preferably comprise a glueing element that is to make contact with a foam section for applying glue to said foam section, said moving means being arranged for moving the foam section in question in a further direction of movement towards and away from the glueing element, said application means and said positioning means associated with the foam section in question comprising centring means fitted with mating centring means on the application means and the positioning means in question for aligning the foam section in question and the glueing element with respect to each other upon placing the foam section in question and the glueing element into contact with each other.

To prevent glue being spread upon application thereof to a foam section, the centring means are preferably arranged for aligning the foam section in question and the glueing element in a direction perpendicular to said further direction of movement before the foam section in question and the glueing element are placed into contact with each other. Generally the centring elements, insofar as they are used for aligning a foam section and a glueing element, are preferably of the same type as the centring elements that, according to a preferred embodiment as described above, function to align two foam sections that are to be glued together.

The above-described preferred embodiments, insofar as they relate to the centring means, can also be used to advantage with prior art devices. Consequently, the present invention also relates to a device for glueing foam sections together, comprising a glueing station provided with first positioning means for positioning a first foam section, second positioning means for positioning a second foam section, application means for applying glue to the first foam section and/or the second foam section, moving means for moving the first positioning means and the second positioning means towards and away from each other in a direction of movement for placing the first foam section and the second foam section into contact with each other for the purpose of glueing together the same and subsequently holding the first and the second foam section in glued-together condition in the second positioning means, characterized in that said first positioning means and said second positioning means comprise centring means having intermating centring means on the respective first and second positioning means for aligning the first foam section and the second foam section element upon placing the first foam section and the second foam section into contact with each other, which may or may not take place in accordance with one of the preferred embodiments as described above. Within this framework, the invention also relates to a device for glueing foam sections together, said device comprising a glueing station provided with first positioning means for positioning a first foam section, second positioning means for positioning a second foam section, application means for applying glue to the first foam section and/or the second foam section, moving means for moving the first positioning means and the second positioning means towards and away from each other in a direction of movement for placing the first foam section and the second foam section into contact with each other for the purpose of glueing together the same and subsequently holding the first and the second foam section in glued-together condition in the second positioning means, characterized in that the application means comprise a glueing element that is to make contact with a foam section for applying glue to said foam section, said moving means being arranged for moving the foam section in question in a further direction of movement towards and away from the glueing element, said application means and said positioning means associated with the foam section in question comprising centring means having intermating centring means on the application means and the positioning means in question for aligning the foam section in question and the glueing element with respect to each other upon placing the foam section in question and the glueing element into contact with each other. The use of centring means may be advantageous not only upon positioning two foam sections to be glued together with respect to each other but also upon applying glue to one of the two foam sections.

The invention will be explained in more detail below by means of the description of a preferred embodiment of a device according to the invention, in which reference is made to figures 1-15, in which: Figures 1-11 are side elevations of the preferred embodiment of the device according to the invention, showing successive steps during the use thereof; Figure 12 is a top plan view of the device of figure 1 ; Figures 13-15 show successive stages of the area A of figure 7 during the alignment of the foam sections that are to be glued together.

Figures 1 and 2 and 12 show the glueing device 1, which comprises a base glueing station 2 and a further glueing station 3. In addition to that, the glueing device 1 is provided with rails 4, on which trolleys 5,6 having wheels 63,64 can move forward and backward. To that end, the trolleys 5,6 are rigidly interconnected by rods 7, with a dual piston-cylinder assembly 10 comprising double-acting piston-cylinder combinations 10a and 10b being used. The end of the piston rod 9a engages a fixed horizontal member 61 that forms part of the base glueing station 2. The end of the piston rod 9b engages the front side 8 of the trolley 5. At the rear end, the piston-cylinder assembly 10 is connected to a cross rod 11, which is provided with wheels 62 at the ends thereof. The wheels 62 run on rails 4. Pulling the piston-cylinder assembly 10a over the piston rod 9a, as it were, and pushing the piston rod 9b out of the piston-cylinder assembly 10b (simultaneously therewith, subsequently thereto or prior thereto), enables the trolleys 5,6 to travel a distance which is twice as large as the stroke of the individual piston rods 9a, 9b and equal to the distance between the base glueing station 2 and the further glueing station 3 (see figures 7-10). It should be noted in explanation of figure 12 that part of the trolley 5 and of the base glueing station 2 are not shown so as to make it possible to show parts positioned thereunder.

Present on the trolley 5, rigidly connected therewith, is an exchangeable lower retainer 12, whilst a corresponding, likewise exchangeable, lower retainer 13 is present on the trolley 6. The lower retainers 12,13 are provided with cavities at the upper side, in the bottom of which cavities suction nozzles are provided for positioning foam sections 14 in'the cavity and retaining them in position therein through suction. A middle foam section 15 is loosely positioned on top of the lower foam section 14 in the lower retainer 12. The lower retainer 13 also retains a lower foam section 14, to which a middle foam section 15 is attached by means of a layer of glue 17. An upper foam section 16 is loosely positioned on the middle foam section 15 associated with the trolley 6 and the lower retainer 13. The manner in which this situation has been effected will be explained below.

Three uprights 18 are present on the trolley 5, on the outer side of the lower retainer 12, said uprights each being provided at their upper end with a male conical centring head 19. The trolley 6, too, is provided at three corresponding positions with three uprights 18 having the same male centring heads 19. In addition to that, three further uprights 20 are present on the trolley 6, the length of which uprights is greater than that of the uprights 18. On the trolley 6, the uprights 18 and 20 are arranged in two rows of three uprights (refer in particular to figure 12).

Each glueing station 2,3 comprises four vertical legs 21 and 22, respectively, disposed in the corner points of a square, seen in top plan view, which legs extend partially above and partially below the rails 4. The spacing between two vertical legs 21,22 has been selected such that the rails 4 can just extend there between, with the trolleys 5, 6 being movable between the vertical legs 21, 22 in question.

Each glueing station 2,3 furthermore comprises a glue application unit 23,24, each comprising a tank 25,26 containing a hot glue 27,28. Glue plates 31,32 are submerged in the glue 27,28 by means of brackets 29,30, which are fixedly connected to the vertical legs 21, 22. The tanks 25,26 can be moved up and down, with the position shown in figure 1 being the upper position, by means of piston-cylinder assemblies 53,44. By way of illustration, reference is made to figure 5 already, which shows the tanks 25,26 in the lower position thereof. Each glue application unit 23, 24 is furthermore provided with three male centring heads 19. The centring heads 19 associated with the glue application unit 23 are located at relative positions corresponding to those of the uprights 18, whilst the centring heads 19 associated with the glue application unit 24 are located at relative positions corresponding to those of the uprights 20.

Each glueing station 2, 3 is furthermore provided at the upper side thereof with an upper retainer section 33,34. The upper retainer sections 33,34 each comprise an upper retainer 35,36 which, like the lower retainers 12,13, are provided with suction nozzles (not shown) in a cavity for retaining a foam section. In this case the upper section 35 is arranged for retaining a middle foam section 15, and the upper retainer 36 is arranged for retaining an upper foam section 16.

The upper retainers 35,36 are suspended from a plate 37, 38. On the outer side of the upper retainer 35, the plate 37 is provided with three downwardly extending centring members 39, one of which is hidden behind the upper retainer 35 in figure 11. The positions of the centring members 39 correspond to those of the uprights 18 on the trolleys 5 and 6. The centring members 39 are therefore intended to mate inter alia with the centring heads 19 associated with the uprights 18.

The plate 38 is likewise provided with three centring members 39, which are located at positions corresponding to those of the uprights 20, however, so as to mate with the centring heads 19 associated with the uprights 20.

The plates 37,38 are suspended from slide plates 40,41 via pins 42,43. figure 13 is a more detailed view of the environment of one such pin 42. The pin 42 has a wide head 44, which is supported with its bottom side on the upper side of the slide plate 40. Holes 45 having a diameter greater than that of the associated pin 42. are provided in the slide plate 40 for each pin 42. As a result, the pin 42 is accommodated in the associated hole 45 with some play. The pin 42 is provided with a bevelled locating edge 46 directly under the head 44. The hole 45 is provided with a corresponding bevel 47 at its upper edge.

Present between the bottom side of the slide plate 40 and the upper side of the plate 37 are compression springs 48, which extend around each pin 42, but which, in a starting position (figure 13), do not abut against the bottom side of the slide plate 40 and are tensionless, therefore. Each centring member 39 comprises a housing 49, within which a female centring head 50 can move up and down. The upper position of the centring head 50 is defined by a stop edge 51. Present inside the housing 49 is a compression spring 52, which opposes upward movement of the centring head 50.

The upper retainer sections 33,34 can be moved in vertical direction along the associated legs 21,22, via guide means 65,66, between an upper position as shown in figure 1 and a lower position as shown in figure 5.

Starting from the situation that is shown in figure 1, the glueing device 1 operates as follows. From the situation that is shown in figure 1, the trolleys 5 and 6 are jointly moved over a distance equal to the spacing between the trolleys to the position that is shown in figure 2 by suitably driving the piston-cylinder assemblies 10a and 10b, in which position the trolley 5 is positioned between the vertical legs 21 of the base glueing station 2 and the trolley 6 is positioned between the vertical legs 22 of the further glueing station 3. Subsequently, the upper retainer sections 33,34 move downwards until the upper retainers 35,36 abut against the upper side of the middle foam section 15 on the trolley 5 and the upper foam section 16 on the trolley 6, respectively.

The interaction between the centring heads 19,50 will be explained in more detail yet with reference to figures 7,13, 14 and 15.

Upon activation of the suction nozzles of the upper retainers 35,36, said upper retainers 35,36 suck the respective foam sections 15,16 against the upper retainers, after which the upper retainer sections 33,34 move up again (figure 3). Subsequently, the trolleys 5,6 are moved back half a stroke again by suitably driving the piston-cylinder assembly 10b (figure 4). As a result, space is cleared for moving the upper retainer sections 33,34 downwards until the bottom side of the middle foam section 15 and the upper foam section 16, respectively, substantially abuts against the glue plates 31,32, to an extent sufficient for applying glue to said foam sections 15,16.

Simultaneously with the downward movement of the upper retainer sections 33,34, the tanks 25,26 are moved downwards by suitably driving the piston-cylinder assemblies 53,54. During and just before the contact between the glue plates 31,32 and the foam sections 15,16, the centring heads 19 associated with the respective glue application units 23,24 and the centring heads 50 of the centring members 39 associated with the respective upper retainer sections 33,34 intermate in a manner to be explained yet with reference to figures 7, 13,14 and 15 (figure 5).

Subsequently, the upper retainer sections 33,34 move up again, as do the tanks 25,26. The middle foam section 15 in the upper retainer 35 and the upper foam section 16 in the upper retainer 36 are now provided with a layer of glue 55,56 on their bottom side. Depending on the type of (hot) glue 27,26 that is used, the foam sections 14,15, 16 to be joined by means of the layer of glue 55,56 must be pressed against each other within a specific number of seconds so as to effect a strong glued joint. To that end, the trolleys 5,6 move ahead another half stroke (back to the position that is shown in figures 2 and 3, therefore), after which the upper mould sections 33,34 are moved down again for placing the facing sides of the lower foam section 14 in the trolley 5 and the upper foam section 15 in the upper retainer 35, with the layer of glue 55 therebetween, into contact with each other and placing the upper side of the middle foam section 15 in the trolley 6 and the upper foam section 16 in the upper retainer 36, with the layer of glue 56 therebetween, into contact with each other.

Figures 13,14, 15 show successive moments of the area A in figure 7 during and just before the foam sections 14,15 are placed into contact with each other. Figure 13 shows a first phase, in which the centring heads 19 and 15 are nearly in contact with each other. As figure 13 shows, the central axes 57,58 of the centring heads 19,58 are not in line but spaced a distance 59 apart. If the foam sections 14,15 would thus be placed into contact with each other, this would mean that the foam sections 14,15 would shift a distance 59 in horizontal direction with respect to each other after the contact between the foam sections 14,15 has been effected, or that the foam sections 14,15 would be incorrectly positioned relative to each other by said distance 59, which would lead to an insufficient dimensional accuracy of the final foam section 14,15, 16 being assembled. Both situations are undesirable.

Because of the contact between the bevelled surfaces of the centring head 19 and the centring head 50, the plate 37 and all the parts that are fixedly connected thereto will be raised relative to the centring head 19, whilst simultaneously the plate 37 and all the parts connected thereto will move sideways over the distance 59 in the direction indicated by the arrow 60, so that the central axes 57,58 will be aligned and consequently the upper retainer 35 and the lower retainer 12 will be positioned in correctly aligned relationship with respect to each other. The latter horizontal movement of the plate 37 is made possible as a result of the fact that the bevel 47 of the pin 42 is lifted from the hole 45, thus enabling lateral movement of the pin 42.

Upon movement of the centring head 50 into the housing 49, the upper end of the spring 48 will come to abut against the bottom side of the slide plate 40, and from that moment the spring 48 will offer resistance against the movement towards each other of the slide played 40 and the plate 37. The spring 48 is more rigid than the spring 52. The movement of the centring head 50 into the housing 49 will continue until the centring head 50 strikes the stop edge 51. The foam sections 14,15 will not come into contact with each other upon further lowering of the guide members 65 until the centring head has struck the stop edge 51, said foam sections 14,15 being pressed together against the action of the compression spring 48, thus ensuring that the foam sections 14,15 are correctly aligned and that consequently no glue will be spread over the boundary surface between the foam sections 14,15. Such spreading of the glue would be highly disadvantageous because of the risk of glue being incorrectly distributed and the glued joint not meeting the applicable requirements. It will be apparent that the same manner of alignment is obtained by cooperation between the centring heads 50 of the upper retainer sections 33,34 and the centring heads 19 associated with the glue application units 23,24.

It should furthermore be noted that the plates 37,38 and the associated upper retainers 35,36 can be exchanged for other plates and upper retainers, enabling a very quick changeover between production processes for different kinds of assembled foam sections. In addition to that it should be noted that the uprights 20 are longer than the uprights 18, because the joint height of the foam sections 14,15, 16 in the further glueing station 3 is greater than that of the foam sections 14, 15 in the base glueing station 2.

After the foam sections 14,15, 16 to be glued together have been pressed together for a few seconds, the suction nozzles in the lower retainers 12,13 are deactivated, whereupon the upper retainer sections 33,33 move upwards again, with the glued-together foam sections 14,15 and the glued-together foam sections 14,15, 16, respectively, now present therein, however.

Then the trolleys 5,6 are moved back again, this time without foam sections present therein. From this situation, the upper retainer section 33 moves downwards, after which the suction nozzles of the upper retainer 35 are deactivated and the suction nozzles of the lower retainer 13 of the trolley 6 are activated, so that the lower retainer 13 can take over the glued-together foam sections 14,15.

Simultaneously therewith, the foam section assembled from the foam sections 14,15, 16 is manually removed from the upper retainer 36 (figure 11). Following that, the trolley 5 is filled with a lower foam section 14 and a middle foam section 15 again, as in figure 1.

Furthermore, an upper foam section 16 is positioned loosely on top of the glued-together foam sections 14,15 and the lower retainer 13, as a result of which the situation that is shown of figure 1 is obtained again.